default size of arraylist

[kiran kumar]

Hi,
what is the default size of arraylist?

[Seetharaman Venkatasamy]

the default size is 1

[Paul Sturrock]

No its not. Try running this:

ArrayList foo = new ArrayList();
System.out.println(foo.size());

and see what you get.

[Seetharaman Venkatasamy]

Hi paul,

yes.you are right.the answare is 1 .but when you add one element to an ArrayList..it will allocate dynamically size 1 right?

please..tell me the default size of vector, hashtable and hashMap

[Seetharaman Venkatasamy]

Originally posted by seetharaman venkatasamy:
Hi paul,

yes.you are right.the answare is 1

sorry answare is 0(wrongly written)

[Paul Sturrock]

but when you add one element to an ArrayList..it will allocate dynamically size 1 right?

It depends on how you add an element. If you use the method add(Object) of the type List the list will be resized. If you use add(int, Object) you will get an IndexOutOfBoundsException.

please..tell me the default size of vector, hashtable and hashMap

You can easily adapt the above program to find this out.

[Christoph Naber]

Are you sure the OP didnt mean "initial capacity"?

If so, this would default to 10, whereas the "default size" would always be 0 unless the

ArrayList(Collection<? extends E> c)

- Constructor is used. Then the size would be (obviously) c.size().

Hava look:
http://java.sun.com/j2se/1.5.0/docs/api/java/util/ArrayList.html

Prost
Christoph

[ June 09, 2008: Message edited by: Christoph Naber ]
[ June 09, 2008: Message edited by: Christoph Naber ]

[Rob Spoor]

Originally posted by Paul Sturrock:
It depends on how you add an element. If you use the method add(Object) of the type List the list will be resized. If you use add(int, Object) you will get an IndexOutOfBoundsException.

Only if the index is not 0 (or more formal, if the index is out of range (index < 0 || index > size()))